]> A YANG Data Model for Traffic Engineering Tunnels, Label Switched Paths and Interfaces Cisco Systems Inc
tsaad.net@gmail.com
Cisco Systems Inc
rgandhi@cisco.com
IBM Corporation
xufeng.liu.ietf@gmail.com
Juniper Networks
vbeeram@juniper.net
Individual
i_bryskin@yahoo.com
Telefonica
oscar.gonzalezdedios@telefonica.com
TEAS Working Group Internet-Draft This document defines a YANG data model for the provisioning and management of Traffic Engineering (TE) tunnels, Label Switched Paths (LSPs), and interfaces. The model covers data that is independent of any technology or dataplane encapsulation and is divided into two YANG modules that cover device-specific, and device independent data. This model covers data for configuration, operational state, remote procedural calls, and event notifications.
Introduction YANG and is a data modeling language that was introduced to define the contents of a conceptual data store that allows networked devices to be managed using NETCONF . YANG has proved relevant beyond its initial confines, as bindings to other interfaces (e.g. RESTCONF ) and encoding other than XML (e.g. JSON) are being defined. Furthermore, YANG data models can be used as the basis of implementation for other interfaces, such as CLI and programmatic APIs. This document describes a YANG data model for Traffic Engineering (TE) tunnels, Label Switched Paths (LSPs), and interfaces. The data model is divided into two YANG modules. The module 'ietf-te.yang' includes data that is generic and device-independent, while the module 'ietf-te-device.yang' includes data that is device-specific. The document describes a high-level relationship between the modules defined in this document, as well as other external protocol YANG modules. The TE generic YANG data model does not include any data specific to a signaling protocol. It is expected other data plane technology model(s) will augment the TE generic YANG data model. Also, it is expected other YANG modules that model TE signaling protocols, such as RSVP-TE (, ), or Segment-Routing TE (SR-TE) will augment the generic TE YANG module.
Terms and Conventions
Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here.
Terminology The following terms are defined in and are used in this specification: client configuration data state data This document also makes use of the following terminology introduced in the YANG Data Modeling Language : augment data model data node
Prefixes in Data Node Names In this document, names of data nodes and other data model objects are prefixed using the standard prefix associated with the corresponding YANG imported modules, as shown in . Prefix YANG module Reference yang ietf-yang-types inet ietf-inet-types rt-types ietf-routing-types te-types ietf-te-types te-packet-types ietf-te-packet-types te ietf-te this document te-dev ietf-te-device this document
Model Tree Diagrams The tree diagrams extracted from the module(s) defined in this document are given in subsequent sections as per the syntax defined in .
Design Considerations This document describes a generic TE YANG data model that is independent of any dataplane technology. One of the design objectives is to allow specific data plane technology models to reuse the TE generic data model and possibly augment it with technology specific data. The elements of the generic TE YANG data model, including TE Tunnels, LSPs, and interfaces have leaf(s) that identify the technology layer where they reside. For example, the LSP encoding type can identify the technology associated with a TE Tunnel or LSP. Also, the generic TE YANG data model does not cover signaling protocol data. The signaling protocol used to instantiate TE LSPs are outside the scope of this document and expected to be covered by augmentations defined in other document(s). The following other design considerations are taken into account with respect to data organization: The generic TE YANG data model 'ietf-te' contains device independent data and can be used to model data off a device (e.g. on a TE controller). When the model is used to manage a specific device, the model contains the TE Tunnels originating from the specific device. When the model is used to manage a TE controller, the 'tunnels' list contains all TE Tunnels and TE tunnel segments originating from device(s) that the TE controller manages. The device-specific TE data is defined in module 'ietf-te-device' as shown in . In general, minimal elements in the model are designated as "mandatory" to allow freedom to vendors to adapt the data model to their specific product implementation. Suitable defaults are specified for all configurable elements. The model declares a number of TE functions as features that can be optionally supported.
State Data Organization The Network Management Datastore Architecture (NMDA) addresses modeling state data for ephemeral objects. This document adopts the NMDA model for configuration and state data representation as per IETF guidelines for new IETF YANG models.
Model Overview The data models defined in this document cover the core TE features that are commonly supported by different vendor implementations. The support of extended or vendor specific TE feature(s) is expected to either be in augmentations, or deviations to this model that are defined in separate documents.
Module Relationship The generic TE YANG data model that is defined in "ietf-te.yang" covers the building blocks that are device independent and agnostic of any specific technology or control plane instances. The TE device model defined in "ietf-te-device.yang" augments the generic TE YANG data model and covers data that is specific to a device -- for example, attributes of TE interfaces, or TE timers that are local to a TE node. The TE data models for specific instances of data plane technology exist in separate YANG modules that augment the generic TE YANG data model. The TE data models for specific instances of signaling protocols are outside the scope of this document and are defined in other documents. For example, the RSVP-TE YANG model augmentation of the TE model is covered in a separate document.
TE YANG Model The generic TE YANG module ('ietf-te') is meant for the management and operation of a TE network. This includes creating, modifying and retrieving information about TE Tunnels, LSPs, and interfaces and their associated attributes (e.g. Administrative-Groups, SRLGs, etc.). A full tree diagram of the TE model is shown in the Appendix in .
Module Structure The 'te' container is the top level container in the 'ietf-te' module. The presence of the 'te' container enables TE function system wide. Below provides further descriptions of containers that exist under the 'te' top level container. There are three further containers grouped under the 'te' container as shown in and described below. globals:
  • The 'globals' container maintains the set of global TE attributes that can be applicable to TE Tunnels and interfaces.
tunnels:
  • The 'tunnels' container includes the list of TE Tunnels that are instantiated. Refer to for further details on the properties of a TE Tunnel.
lsps:
  • The 'lsps' container includes the list of TE LSP(s) that are instantiated for TE Tunnels. Refer to for further details on the properties of a TE LSP.
The model also contains two Remote Procedure Calls (RPCs) as shown in and described below. tunnels-path-compute:
  • A RPC to request path computation for a specific TE Tunnel. The RPC allows requesting path computation using atomic and stateless operation. A tunnel may also be configured in 'compute-only' mode to provide stateful path updates - see for further details.
tunnels-action:
  • An RPC to request a specific action (e.g. reoptimize, or tear-and-setup) to be taken on a specific tunnel or all tunnels.
shows the relationships of these containers and RPCs within the 'ietf-te' module.
TE Globals The 'globals' container covers properties that control a TE feature's behavior system-wide, and its respective state as shown in and described in the text that follows.
named-admin-groups:
  • A YANG container for the list of named (extended) administrative groups that may be applied to TE links.
named-srlgs:
  • A YANG container for the list of named Shared Risk Link Groups (SRLGs) that may be applied to TE links.
named-path-constraints:
  • A YANG container for a list of named path constraints. Each named path constraint is composed of a set of constraints that can be applied during path computation. A named path constraint can be applied to multiple TE Tunnels. Path constraints may also be specified directly under the TE Tunnel. The path constraints specified under the TE Tunnel take precedence over the path constraints derived from the referenced named path constraint. A named path constraint entry can be formed of the path constraints shown in :
    • name: A YANG leaf that holds the named path constraint entry. This is unique in the list and used as a key. te-bandwidth: A YANG container that holds the technology agnostic TE bandwidth constraint. link-protection: A YANG leaf that holds the link protection type constraint required for the links to be included in the computed path. setup/hold priority: YANG leafs that hold the LSP setup and hold admission priority as defined in . signaling-type: A YANG leaf that holds the LSP setup type, such as RSVP-TE or SR. path-metric-bounds: A YANG container that holds the set of metric bounds applicable on the computed TE tunnel path. path-affinities-values: A YANG container that holds the set of affinity values and mask to be used during path computation. path-affinity-names: A YANG container that holds the set of named affinity constraints and corresponding inclusion or exclusion instructions for each to be used during path computation. path-srlgs-lists: A YANG container that holds the set of SRLG values and corresponding inclusion or exclusion instructions to be used during path computation. path-srlgs-names: A YANG container that holds the set of named SRLG constraints and corresponding inclusion or exclusion instructions for each to be used during path computation. disjointness: The level of resource disjointness constraint that the secondary path of a TE tunnel has to adhere to. explicit-route-objects-always: A YANG container that contains two route objects lists: 'route-object-exclude-always': a list of route entries to always exclude from the path computation. 'route-object-include-exclude': a list of route entries to include or exclude in the path computation.
      • The 'route-object-include-exclude' is used to configure constraints on which route objects (e.g., nodes, links) are included or excluded in the path computation.
      • The interpretation of an empty 'route-object-include-exclude' list depends on the TE Tunnel (end-to-end or Tunnel Segment) and on the specific path, according to the following rules:
      • An empty 'route-object-include-exclude' list for the primary path of an end-to-end TE Tunnel indicates that there are no route objects to be included or excluded in the path computation. An empty 'route-object-include-exclude' list for the primary path of a TE Tunnel Segment indicates that no primary LSP is required for that TE Tunnel. An empty 'route-object-include-exclude' list for a reverse path means it always follows the forward path (i.e., the TE Tunnel is co-routed). When the 'route-object-include-exclude' list is not empty, the reverse path is routed independently of the forward path. An empty 'route-object-include-exclude' list for the secondary (forward) path indicates that the secondary path has the same endpoints as the primary path.
      path-in-segment: A YANG container that contains a list of label restrictions that have to be taken into considerations when crossing domains. This TE tunnel segment in this case is being stitched to the upstream TE tunnel segment. path-out-segment: A YANG container that contains a list of label restrictions that have to be taken into considerations when crossing domains. The TE tunnel segment in this case is being stitched to the downstream TE tunnel segment.
TE Tunnels The 'tunnels' container holds the list of TE Tunnels that are provisioned on devices in the network as shown in .
When the model is used to manage a specific device, the 'tunnels' list contains the TE Tunnels originating from the specific device. When the model is used to manage a TE controller, the 'tunnels' list contains all TE Tunnels and TE tunnel segments originating from device(s) that the TE controller manages. The TE Tunnel model allows the configuration and management of the following TE tunnel objects: TE Tunnel:
  • A YANG container of one or more TE LSPs established between the source and destination TE Tunnel termination points.
TE Path:
  • An engineered path that once instantiated in the forwarding plane can be used to forward traffic from the source to the destination TE Tunnel termination points.
TE LSP:
  • A TE LSP is a connection-oriented service established over a TE Path and that allows the delivery of traffic between the TE Tunnel source and destination termination points.
TE Tunnel Segment:
  • A part of a multi-domain TE Tunnel that is within a specific network domain.
The TE Tunnel has a number of attributes that are set directly under the tunnel (as shown in ). The main attributes of a TE Tunnel are described below: operational-state:
  • A YANG leaf that holds the operational state of the tunnel.
name:
  • A YANG leaf that holds the name of a TE Tunnel. The name of the TE Tunnel uniquely identifies the tunnel within the TE tunnel list. The name of the TE Tunnel can be formatted as a Uniform Resource Indicator (URI) by including the namespace to ensure uniqueness of the name amongst all the TE Tunnels present on devices and controllers.
alias:
  • A YANG leaf that holds an alternate name to the TE tunnel. Unlike the TE tunnel name, the alias can be modified at any time during the lifetime of the TE tunnel.
identifier:
  • A YANG leaf that holds an identifier of the tunnel. This identifier is unique amongst tunnels originated from the same ingress device.
color:
  • A YANG leaf that holds the color associated with the TE tunnel. The color is used to map or steer services that carry matching color on to the TE tunnel as described in .
admin-state:
  • A YANG leaf that holds the tunnel administrative state. The administrative status in state datastore transitions to 'tunnel-admin-up' when the tunnel used by the client layer, and to 'tunnel-admin-down' when it is not used by the client layer.
operational-state:
  • A YANG leaf that holds the tunnel operational state.
encoding/switching:
  • The 'encoding' and 'switching-type' are YANG leafs that define the specific technology in which the tunnel operates in as described in .
source/destination:
  • YANG leafs that define the tunnel source and destination node endpoints.
src-tunnel-tp-id/dst-tunnel-tp-id:
  • YANG leafs that hold the identifiers of source and destination TE Tunnel Termination Points (TTPs) residing on the source and destination nodes. The TTP identifiers are optional on nodes that have a single TTP per node. For example, TTP identifiers are optional for packet (IP/MPLS) routers.
bidirectional:
  • A YANG leaf that when present indicates the LSPs of a TE Tunnel are bidirectional and co-routed.
controller:
  • A YANG container that holds tunnel data relevant to an optional external TE controller that may initiate or control a tunnel. This target node may be augmented by external module(s), for example, to add data for PCEP initiated and/or delegated tunnels.
reoptimize-timer:
  • A YANG leaf to set the interval period for tunnel reoptimization.
association-objects:
  • A YANG container that holds the set of associations of the TE Tunnel to other TE Tunnels. Associations at the TE Tunnel level apply to all paths of the TE Tunnel. The TE tunnel associations can be overridden by associations configured directly under the TE Tunnel path.
protection:
  • A YANG container that holds the TE Tunnel protection properties.
restoration:
  • A YANG container that holds the TE Tunnel restoration properties.
te-topology-identifier:
  • A YANG container that holds the topology identifier associated with the topology where paths for the TE tunnel are computed.
hierarchy:
  • A YANG container that holds hierarchy related properties of the TE Tunnel. A TE LSP can be set up in MPLS or Generalized MPLS (GMPLS) networks to be used as a TE link to carry traffic in other (client) networks . In this case, the model introduces the TE Tunnel hierarchical link endpoint parameters to identify the specific link in the client layer that the underlying TE Tunnel is associated with. The hierarchy container includes the following:
    • dependency-tunnels: A set of hierarchical TE Tunnels provisioned or to be provisioned in the immediate lower layer that this TE tunnel depends on for multi-layer path computation. A dependency TE Tunnel is provisioned if and only if it is used (selected by path computation) at least by one client layer TE Tunnel. The TE link in the client layer network topology supported by a dependent TE Tunnel is dynamically created only when the dependency TE Tunnel is actually provisioned. hierarchical-link: A YANG container that holds the identity of the hierarchical link (in the client layer) that is supported by this TE Tunnel. The endpoints of the hierarchical link are defined by TE tunnel source and destination node endpoints. The hierarchical link can be identified by its source and destination link termination point identifiers.
primary-paths:
  • A YANG container that holds the list of primary paths. A primary path is identified by 'name'. A primary path is selected from the list to instantiate a primary forwarding LSP for the tunnel. The list of primary paths is visited by order of preference. A primary path has the following attributes:
  • primary-reverse-path: A YANG container that holds properties of the primary reverse path. The reverse path is applicable to bidirectional TE Tunnels.
  • candidate-secondary-paths: A YANG container that holds a list of candidate secondary paths which may be used for the primary path to support path protection. The candidate secondary path(s) reference path(s) from the tunnel secondary paths list. The preference of the secondary paths is specified within the list and dictates the order of visiting the secondary path from the list. The attributes of a secondary path can be defined separately from the primary path. The attributes of a secondary path will be inherited from the associated 'active' primary when not explicitly defined for the secondary path.
secondary-paths:
  • A YANG container that holds the set of secondary paths. A secondary path is identified by 'name'. A secondary path can be referenced from the TE Tunnel's 'candidate-secondary-path' list.
secondary-reverse-paths:
  • A YANG container that holds the set of secondary reverse paths. A secondary reverse path is identified by 'name'. A secondary reverse path can be referenced from the TE Tunnel's 'candidate-secondary-reverse-paths' list. A secondary reverse path contains attributes similar to a primary path.
The following set of common path attributes are shared for primary (forward and reverse) and secondary paths: path-computation-method:
  • A YANG leaf that specifies the method used for computing the TE path.
path-computation-server:
  • A YANG container that holds the path computation server properties when the path is externally queried.
compute-only:
  • A path of a TE Tunnel is, by default, provisioned so that it can instantiated in the forwarding plane so that it can carry traffic as soon as a valid path is computed. In some cases, a TE path may be configured only for the purpose of computing a path and reporting it without the need to instantiate the LSP or commit any resources. In such a case, the path is configured in 'compute-only' mode to distinguish it from the default behavior. A 'compute-only' path is configured as a usual with the associated per path constraint(s) and properties on a device or TE controller. The device or TE controller computes the feasible path(s) subject to configured constraints. A client may query the 'compute-only' computed path properties 'on-demand', or alternatively, can subscribe to be notified of computed path(s) and whenever the path properties change.
use-path-computation:
  • A YANG leaf that indicates whether or not path computation is to be used for a specified path.
lockdown:
  • A YANG leaf that when set indicates the existing path should not be reoptimized after a failure on any of its traversed links.
path-scope:
  • A YANG leaf that specifies the path scope if segment or an end-to-end path.
preference:
  • A YANG leaf that specifies the preference for the path. The lower the number higher the preference.
k-requested-paths:
  • A YANG leaf that specifies the number of k-shortest-paths requested from the path computation server and returned sorted by its optimization objective.
association-objects:
  • A YANG container that holds a list of tunnel association properties.
optimizations:
  • A YANG container that holds the optimization objectives that path computation will use to select a path.
named-path-constraint:
  • A YANG leafref that references an entry from the global list of named path constraints.
te-bandwidth:
  • A YANG container that holds the path bandwidth (see ).
link-protection:
  • A YANG leaf that specifies the link protection type required for the links to be included the computed path (see ).
setup/hold-priority:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
signaling-type:
  • see description provided in . This value overrides the provided one in the referenced named-path-constraint.
path-metric-bounds:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
path-affinities-values:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
path-affinity-names:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
path-srlgs-lists:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
path-srlgs-names:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
disjointness:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
explicit-route-objects-always:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
path-in-segment:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
path-out-segment:
  • see description provided in . These values override those provided in the referenced named-path-constraint.
computed-paths-properties: > A YANG container that holds properties for the list of computed paths. computed-path-error-infos:
  • A YANG container that holds a list of errors related to the path.
lsp-provisioning-error-infos:
  • A YANG container that holds the list of LSP provisioning error information.
lsps:
  • A YANG container that holds a list of LSPs that have been instantiated for this specific path.
In addition to the path common attributes, the primary path has the following attributes that are not present in the secondary path: Only the primary path contains the list of 'candidate-secondary-paths' that can protect the primary path. Only the primary path can contain a primary-reverse-path associated with the primary path (and its associated list of 'candidate-secondary-reverse-path').
TE LSPs The 'lsps' container includes the set of TE LSP(s) that have been instantiated. A TE LSP is identified by a 3-tuple ('tunnel-name', 'lsp-id', 'node'). When the model is used to manage a specific device, the 'lsps' list contains all TE LSP(s) that traverse the device (including ingressing, transiting and egressing the device). When the model is used to manage a TE controller, the 'lsps' list contains all TE LSP(s) that traverse all network devices (including ingressing, transiting and egressing the device) that the TE controller manages.
Tree Diagram shows the tree diagram of depth=4 for the generic TE YANG model defined in modules 'ietf-te.yang'. The full tree diagram is shown in .
YANG Module The generic TE YANG module 'ietf-te' imports the following modules: ietf-yang-types and ietf-inet-types defined in ietf-te-types defined in This module references the following documents: , , , , , , , , , , , and .
file "ietf-te@2022-10-12.yang" module ietf-te { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-te"; /* Replace with IANA when assigned */ prefix te; /* Import TE generic types */ import ietf-te-types { prefix te-types; reference "RFC8776: Common YANG Data Types for Traffic Engineering."; } import ietf-inet-types { prefix inet; reference "RFC6991: Common YANG Data Types."; } import ietf-yang-types { prefix yang; reference "RFC6991: Common YANG Data Types."; } organization "IETF Traffic Engineering Architecture and Signaling (TEAS) Working Group."; contact "WG Web: WG List: Editor: Tarek Saad Editor: Rakesh Gandhi Editor: Vishnu Pavan Beeram Editor: Himanshu Shah Editor: Xufeng Liu Editor: Igor Bryskin "; description "YANG data module for TE configuration, state, and RPCs. The model fully conforms to the Network Management Datastore Architecture (NMDA). Copyright (c) 2022 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Revised BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices."; // RFC Ed.: replace XXXX with actual RFC number and remove this // note. // RFC Ed.: update the date below with the date of RFC publication // and remove this note. revision 2022-10-12 { description "Initial revision for the TE generic YANG module."; reference "RFCXXXX: A YANG Data Model for Traffic Engineering Tunnels and Interfaces."; } typedef tunnel-ref { type leafref { path "/te:te/te:tunnels/te:tunnel/te:name"; } description "This type is used by data models that need to reference configured TE tunnel."; } typedef te-gen-node-id { type union { type te-types:te-node-id; type inet:ip-address; } description "Generic type that identifies a node in a TE topology."; } /** * TE tunnel generic groupings */ grouping te-generic-node-id { description "A reusable grouping for a TE generic node identifier."; leaf id { type te-gen-node-id; description "The identifier of the node. Can be represented as IP address or dotted quad address."; } leaf type { type enumeration { enum ip { description "IP address representation of the node identifier."; } enum dotted-quad { description "Dotted quad address representation of the node identifier."; } } description "Type of node identifier representation."; } } grouping path-common-properties { description "Common path attributes."; leaf name { type string; description "TE path name."; } leaf path-computation-method { type identityref { base te-types:path-computation-method; } default "te-types:path-locally-computed"; description "The method used for computing the path, either locally computed, queried from a server or not computed at all (explicitly configured)."; } container path-computation-server { when "derived-from-or-self(../path-computation-method, " + "'te-types:path-externally-queried')" { description "The path-computation server when the path is externally queried."; } uses te-generic-node-id; description "Address of the external path computation server."; } leaf compute-only { type empty; description "When present, the path is computed and updated whenever the topology is updated. No resources are committed or reserved in the network."; } leaf use-path-computation { when "derived-from-or-self(../path-computation-method, " + "'te-types:path-locally-computed')"; type boolean; default "true"; description "When 'true' indicates the path is dynamically computed and/or validated against the Traffic-Engineering Database (TED), and when 'false' indicates no path expansion or validation against the TED is required."; } leaf lockdown { type empty; description "When present, indicates no reoptimization to be attempted for this path."; } leaf path-scope { type identityref { base te-types:path-scope-type; } default "te-types:path-scope-end-to-end"; config false; description "Indicates whether the path is a segment or portion of of the full path., or is the an end-to-end path for the TE Tunnel."; } } /* This grouping is re-used in path-computation rpc */ grouping path-compute-info { description "Attributes used for path computation request."; uses tunnel-associations-properties; uses te-types:generic-path-optimization; leaf named-path-constraint { if-feature "te-types:named-path-constraints"; type leafref { path "/te:te/te:globals/te:named-path-constraints/" + "te:named-path-constraint/te:name"; } description "Reference to a globally defined named path constraint set."; } uses path-constraints-common; } /* This grouping is re-used in path-computation rpc */ grouping path-forward-properties { description "The path preference."; leaf preference { type uint8 { range "1..255"; } default "1"; description "Specifies a preference for this path. The lower the number higher the preference."; } leaf co-routed { when "/te:te/te:tunnels/te:tunnel/te:bidirectional = 'true'" { description "Applicable to bidirectional tunnels only."; } type empty; description "Indicates whether the reverse path must to be co-routed with the primary."; } } /* This grouping is re-used in path-computation rpc */ grouping k-requested-paths { description "The k-shortest paths requests."; leaf k-requested-paths { type uint8; default "1"; description "The number of k-shortest-paths requested from the path computation server and returned sorted by its optimization objective."; } } grouping path-state { description "TE per path state parameters."; uses path-computation-response; container lsp-provisioning-error-infos { config false; description "LSP provisioning error information."; list lsp-provisioning-error-info { description "List of LSP provisioning error info entries."; leaf error-reason { type identityref { base te-types:lsp-provisioning-error-reason; } description "LSP provision error type."; } leaf error-description { type string; description "The textual representation of the error occurred during path computation."; } leaf error-timestamp { type yang:date-and-time; description "Timestamp of when the reported error occurred."; } leaf error-node-id { type te-types:te-node-id; description "Node identifier of node where error occurred."; } leaf error-link-id { type te-types:te-tp-id; description "Link ID where the error occurred."; } leaf lsp-id { type uint16; description "The LSP-ID for which path computation was performed."; } } } container lsps { config false; description "The TE LSPs container."; list lsp { key "node lsp-id"; description "List of LSPs associated with the tunnel."; leaf tunnel-name { type leafref { path "/te:te/te:lsps/te:lsp/te:tunnel-name"; } description "TE tunnel name."; } leaf node { type leafref { path "/te:te/te:lsps/te:lsp[tunnel-name=" + "current()/../te:tunnel-name][lsp-id=" + "current()/../te:lsp-id]/te:node"; } description "The node where the LSP state resides on."; } leaf lsp-id { type leafref { path "/te:te/te:lsps/te:lsp[tunnel-name=" + "current()/../tunnel-name]/te:lsp-id"; } description "The TE LSP identifier."; } } } } /* This grouping is re-used in path-computation rpc */ grouping path-computation-response { description "Attributes reported by path computation response."; container computed-paths-properties { config false; description "Computed path properties container."; list computed-path-properties { key "k-index"; description "List of computed paths."; leaf k-index { type uint8; description "The k-th path returned from the computation server. A lower k value path is more optimal than higher k value path(s)"; } uses te-types:generic-path-properties { augment "path-properties" { description "additional path properties returned by path computation."; uses te-types:te-bandwidth; leaf disjointness-type { type te-types:te-path-disjointness; config false; description "The type of resource disjointness. When reported for a primary path, it represents the minimum level of disjointness of all the secondary paths. When reported for a secondary path, it represents the disjointness of the secondary path."; } } } } } container computed-path-error-infos { config false; description "Path computation information container."; list computed-path-error-info { description "List of path computation info entries."; leaf error-description { type string; description "Textual representation of the error occurred during path computation."; } leaf error-timestamp { type yang:date-and-time; description "Timestamp of last path computation attempt."; } leaf error-reason { type identityref { base te-types:path-computation-error-reason; } description "Reason for the path computation error."; } } } } grouping protection-restoration-properties { description "Protection and restoration parameters."; container protection { description "Protection parameters."; leaf enable { type boolean; description "A flag to specify if LSP protection is enabled."; reference "RFC4427"; } leaf protection-type { type identityref { base te-types:lsp-protection-type; } default "te-types:lsp-protection-unprotected"; description "LSP protection type."; } leaf protection-reversion-disable { type boolean; default "false"; description "Disable protection reversion to working path."; } leaf hold-off-time { type uint32; units "milli-seconds"; description "The time between the declaration of an SF or SD condition and the initialization of the protection switching algorithm."; reference "RFC4427"; } leaf wait-to-revert { type uint16; units "seconds"; description "Time to wait before attempting LSP reversion."; reference "RFC4427"; } leaf aps-signal-id { type uint8 { range "1..255"; } default "1"; description "The APS signal number used to reference the traffic of this tunnel. The default value for normal traffic is 1. The default value for extra-traffic is 255. If not specified, non-default values can be assigned by the server, if and only if, the server controls both endpoints."; reference "RFC4427"; } } container restoration { description "Restoration parameters."; leaf restoration-type { type identityref { base te-types:lsp-restoration-type; } default "te-types:lsp-restoration-restore-any"; description "LSP restoration type."; } leaf restoration-scheme { type identityref { base te-types:restoration-scheme-type; } default "te-types:restoration-scheme-preconfigured"; description "LSP restoration scheme."; } leaf restoration-reversion-disable { type boolean; default "false"; description "Disable restoration reversion to working path."; } leaf hold-off-time { type uint32; units "milli-seconds"; description "The time between the declaration of an SF or SD condition and the initialization of the protection switching algorithm."; reference "RFC4427"; } leaf wait-to-restore { type uint16; units "seconds"; description "Time to wait before attempting LSP restoration."; reference "RFC4427"; } leaf wait-to-revert { type uint16; units "seconds"; description "Time to wait before attempting LSP reversion."; reference "RFC4427"; } } } grouping tunnel-associations-properties { description "TE tunnel association grouping."; container association-objects { description "TE tunnel associations."; list association-object { key "association-key"; unique "type id source/id source/type"; description "List of association base objects."; reference "RFC4872"; leaf association-key { type string; description "Association key used to identify a specific association in the list"; } leaf type { type identityref { base te-types:association-type; } description "Association type."; reference "RFC4872"; } leaf id { type uint16; description "Association identifier."; reference "RFC4872"; } container source { uses te-generic-node-id; description "Association source."; reference "RFC4872"; } } list association-object-extended { key "association-key"; unique "type id source/id source/type global-source extended-id"; description "List of extended association objects."; reference "RFC6780"; leaf association-key { type string; description "Association key used to identify a specific association in the list"; } leaf type { type identityref { base te-types:association-type; } description "Association type."; reference "RFC4872, RFC6780"; } leaf id { type uint16; description "Association identifier."; reference "RFC4872, RFC6780"; } container source { uses te-generic-node-id; description "Association source."; reference "RFC4872, RFC6780"; } leaf global-source { type uint32; description "Association global source."; reference "RFC6780"; } leaf extended-id { type yang:hex-string; description "Association extended identifier."; reference "RFC6780"; } } } } /* This grouping is re-used in path-computation rpc */ grouping tunnel-common-attributes { description "Common grouping to define the TE tunnel parameters"; leaf source { type te-types:te-node-id; description "TE tunnel source node ID."; } leaf destination { type te-types:te-node-id; description "TE tunnel destination node identifier."; } leaf src-tunnel-tp-id { type binary; description "TE tunnel source termination point identifier."; } leaf dst-tunnel-tp-id { type binary; description "TE tunnel destination termination point identifier."; } leaf bidirectional { type boolean; default "false"; description "Indicates a bidirectional co-routed LSP."; } } /* This grouping is re-used in path-computation rpc */ grouping tunnel-hierarchy-properties { description "A grouping for TE tunnel hierarchy information."; container hierarchy { description "Container for TE hierarchy related information."; container dependency-tunnels { description "List of tunnels that this tunnel can be potentially dependent on."; list dependency-tunnel { key "name"; description "A tunnel entry that this tunnel can potentially depend on."; leaf name { type leafref { path "/te:te/te:tunnels/te:tunnel/te:name"; require-instance false; } description "Dependency tunnel name. The tunnel may not have been instantiated yet."; } uses te-types:encoding-and-switching-type; } } container hierarchical-link { description "Identifies a hierarchical link (in client layer) that this tunnel is associated with. By default, the topology of the hierarchical link is the same topology of the tunnel;"; reference "RFC4206"; leaf enable { type boolean; default "false"; description "Enables the hierarchical link properties supported by this tunnel"; } leaf local-te-node-id { type te-types:te-node-id; description "The local TE node identifier."; } leaf local-te-link-tp-id { type te-types:te-tp-id; description "The local TE link termination point identifier."; } leaf remote-te-node-id { type te-types:te-node-id; description "Remote TE node identifier."; } uses te-types:te-topology-identifier { description "The topology identifier where the hierarchical link supported by this TE tunnel is instantiated."; } } } } grouping path-constraints-common { description "Global named path constraints configuration grouping."; uses te-types:common-path-constraints-attributes { description "The constraints applicable to the path. This includes: - The path bandwidth constraint - The path link protection type constraint - The path setup/hold priority constraint - path signaling type constraint - path metric bounds constraint. The unit of path metric bound is interpreted in the context of the metric-type. For example for metric-type 'path-metric-loss', the bound is multiples of the basic unit 0.000003% as described in RFC7471 for OSPF, and RFC8570 for ISIS. - path affinity constraints - path SRLG constraints"; } uses te-types:generic-path-disjointness; uses te-types:path-constraints-route-objects; container path-in-segment { presence "The end-to-end tunnel starts in a previous domain; this tunnel is a segment in the current domain."; description "If an end-to-end tunnel crosses multiple domains using the same technology, some additional constraints have to be taken in consideration in each domain. This TE tunnel segment is stitched to the upstream TE tunnel segment."; uses te-types:label-set-info; } container path-out-segment { presence "The end-to-end tunnel is not terminated in this domain; this tunnel is a segment in the current domain."; description "If an end-to-end tunnel crosses multiple domains using the same technology, some additional constraints have to be taken in consideration in each domain. This TE tunnel segment is stitched to the downstream TE tunnel segment."; uses te-types:label-set-info; } } /** * TE container */ container te { description "TE global container."; leaf enable { type boolean; default "false"; description "Enables the TE component features."; } /* TE Global Data */ container globals { description "Globals TE system-wide configuration data container."; container named-admin-groups { description "TE named admin groups container."; list named-admin-group { if-feature "te-types:extended-admin-groups"; if-feature "te-types:named-extended-admin-groups"; key "name"; description "List of named TE admin-groups."; leaf name { type string; description "A string name that uniquely identifies a TE interface named admin-group."; } leaf bit-position { type uint32; description "Bit position representing the administrative group."; reference "RFC3209 and RFC7308"; } } } container named-srlgs { description "TE named SRLGs container."; list named-srlg { if-feature "te-types:named-srlg-groups"; key "name"; description "A list of named SRLG groups."; leaf name { type string; description "A string name that uniquely identifies a TE interface named SRLG."; } leaf value { type te-types:srlg; description "An SRLG value."; } leaf cost { type uint32; description "SRLG associated cost. Used during path to append the path cost when traversing a link with this SRLG."; } } } container named-path-constraints { description "TE named path constraints container."; list named-path-constraint { if-feature "te-types:named-path-constraints"; key "name"; leaf name { type string; description "A string name that uniquely identifies a path constraint set."; } uses path-constraints-common; description "A list of named path constraints."; } } } /* TE Tunnel Data */ container tunnels { description "Tunnels TE configuration data container."; list tunnel { key "name"; description "The list of TE tunnels."; leaf name { type string; description "TE tunnel name."; } leaf alias { type string; description "An alternate name of the TE tunnel that can be modified anytime during its lifetime."; } leaf identifier { type uint32; description "TE tunnel Identifier."; reference "RFC3209"; } leaf color { type uint32; description "The color associated with the TE tunnel."; reference "RFC9012"; } leaf description { type string; default "None"; description "Textual description for this TE tunnel."; } leaf admin-state { type identityref { base te-types:tunnel-admin-state-type; } default "te-types:tunnel-admin-state-up"; description "TE tunnel administrative state."; } leaf operational-state { type identityref { base te-types:tunnel-state-type; } config false; description "TE tunnel operational state."; } uses te-types:encoding-and-switching-type; uses tunnel-common-attributes; container controller { description "Contains tunnel data relevant to external controller(s). This target node may be augmented by external module(s), for example, to add data for PCEP initiated and/or delegated tunnels."; leaf protocol-origin { type identityref { base te-types:protocol-origin-type; } description "The protocol origin for instantiating the tunnel."; } leaf controller-entity-id { type string; description "An identifier unique within the scope of visibility that associated with the entity that controls the tunnel."; reference "RFC8232"; } } leaf reoptimize-timer { type uint16; units "seconds"; description "Frequency of reoptimization of a traffic engineered LSP."; } uses tunnel-associations-properties; uses protection-restoration-properties; uses te-types:tunnel-constraints; uses tunnel-hierarchy-properties; container primary-paths { description "The set of primary paths."; reference "RFC4872"; list primary-path { key "name"; description "List of primary paths for this tunnel."; uses path-common-properties; uses path-forward-properties; uses k-requested-paths; uses path-compute-info; uses path-state; container primary-reverse-path { when "../../../te:bidirectional = 'false'"; description "The reverse primary path properties."; uses path-common-properties; uses path-compute-info; uses path-state; container candidate-secondary-reverse-paths { when "../../../../te:bidirectional = 'false'"; description "The set of referenced candidate reverse secondary paths from the full set of secondary reverse paths which may be used for this primary path."; list candidate-secondary-reverse-path { key "secondary-path"; ordered-by user; description "List of candidate secondary reverse path(s)"; leaf secondary-path { type leafref { path "../../../../../../" + "te:secondary-reverse-paths/" + "te:secondary-reverse-path/te:name"; } description "A reference to the secondary reverse path that should be utilised when the containing primary reverse path option is in use."; } } } } container candidate-secondary-paths { description "The set of candidate secondary paths which may be used for this primary path. When secondary paths are specified in the list the path of the secondary LSP in use must be restricted to those path options referenced. The priority of the secondary paths is specified within the list. Higher priority values are less preferred - that is to say that a path with priority 0 is the most preferred path. In the case that the list is empty, any secondary path option may be utilised when the current primary path is in use."; list candidate-secondary-path { key "secondary-path"; ordered-by user; description "List of candidate secondary paths for this tunnel."; leaf secondary-path { type leafref { path "../../../../../te:secondary-paths/" + "te:secondary-path/te:name"; } description "A reference to the secondary path that should be utilised when the containing primary path option is in use."; } leaf active { type boolean; config false; description "Indicates the current active path option that has been selected of the candidate secondary paths."; } } } } } container secondary-paths { description "The set of secondary paths."; reference "RFC4872"; list secondary-path { key "name"; description "List of secondary paths for this tunnel."; uses path-common-properties; uses path-forward-properties; uses path-compute-info; uses protection-restoration-properties; uses path-state; } } container secondary-reverse-paths { description "The set of secondary reverse paths."; list secondary-reverse-path { key "name"; description "List of secondary paths for this tunnel."; uses path-common-properties; uses path-compute-info; uses protection-restoration-properties; uses path-state; } } action tunnel-action { description "Tunnel action."; input { leaf action-type { type identityref { base te-types:tunnel-actions-type; } description "Tunnel action type."; } } output { leaf action-result { type identityref { base te-types:te-action-result; } description "The result of the tunnel action operation."; } } } action protection-external-commands { input { leaf protection-external-command { type identityref { base te-types:protection-external-commands; } description "Protection external command."; } leaf protection-group-ingress-node { type boolean; default "true"; description "When 'true', indicates that the action is applied on ingress node. By default, the action applies to the ingress node only."; } leaf protection-group-egress-node { type boolean; default "false"; description "When set to 'true', indicates that the action is applied on egress node. By default, the action applies to the ingress node only."; } leaf path-name { type string; description "The name of the path that the external command applies to."; } leaf traffic-type { type enumeration { enum normal-traffic { description "The manual-switch or forced-switch command applies to the normal traffic (this Tunnel)."; } enum null-traffic { description "The manual-switch or forced-switch command applies to the null traffic."; } enum extra-traffic { description "The manual-switch or forced-switch command applies to the extra traffic (the extra-traffic Tunnel sharing protection bandwidth with this Tunnel)."; } } description "Indicates whether the manual-switch or forced-switch commands applies to the normal traffic, the null traffic or the extra-traffic."; reference "RFC4427"; } leaf extra-traffic-tunnel-ref { type tunnel-ref; description "In case there are multiple extra-traffic tunnels sharing protection bandwidth with this Tunnel (m:n protection), represents which extra-traffic Tunnel the manual-switch or forced-switch to extra-traffic command applies to."; } } } } } /* TE LSPs Data */ container lsps { config false; description "TE LSPs state container."; list lsp { key "tunnel-name lsp-id node"; unique "source destination tunnel-id lsp-id " + "extended-tunnel-id"; description "List of LSPs associated with the tunnel."; leaf tunnel-name { type string; description "The TE tunnel name."; } leaf lsp-id { type uint16; description "Identifier used in the SENDER_TEMPLATE and the FILTER_SPEC that can be changed to allow a sender to share resources with itself."; reference "RFC3209"; } leaf node { type te-types:te-node-id; description "The node where the TE LSP state resides on."; } leaf source { type te-types:te-node-id; description "Tunnel sender address extracted from SENDER_TEMPLATE object."; reference "RFC3209"; } leaf destination { type te-types:te-node-id; description "The tunnel endpoint address."; reference "RFC3209"; } leaf tunnel-id { type uint16; description "The tunnel identifier that remains constant over the life of the tunnel."; reference "RFC3209"; } leaf extended-tunnel-id { type yang:dotted-quad; description "The LSP Extended Tunnel ID."; reference "RFC3209"; } leaf operational-state { type identityref { base te-types:lsp-state-type; } description "The LSP operational state."; } leaf signaling-type { type identityref { base te-types:path-signaling-type; } description "The signaling protocol used to set up this LSP."; } leaf origin-type { type enumeration { enum ingress { description "Origin ingress."; } enum egress { description "Origin egress."; } enum transit { description "Origin transit."; } } description "The origin of the LSP relative to the location of the local switch in the path."; } leaf lsp-resource-status { type enumeration { enum primary { description "A primary LSP is a fully established LSP for which the resource allocation has been committed at the data plane."; } enum secondary { description "A secondary LSP is an LSP that has been provisioned in the control plane only; e.g. resource allocation has not been committed at the data plane."; } } description "LSP resource allocation state."; reference "RFC4872, section 4.2.1"; } leaf lockout-of-normal { type boolean; description "When set to 'true', it represents a lockout of normal traffic external command. When set to 'false', it represents a clear lockout of normal traffic external command. The lockout of normal traffic command applies to this Tunnel."; reference "RFC4427"; } leaf freeze { type boolean; description "When set to 'true', it represents a freeze external command. When set to 'false', it represents a clear freeze external command. The freeze command applies to all the Tunnels which are sharing the protection resources with this Tunnel."; reference "RFC4427"; } leaf lsp-protection-role { type enumeration { enum working { description "A working LSP must be a primary LSP whilst a protecting LSP can be either a primary or a secondary LSP. Also, known as protected LSPs when working LSPs are associated with protecting LSPs."; } enum protecting { description "A secondary LSP is an LSP that has been provisioned in the control plane only; e.g. resource allocation has not been committed at the data plane."; } } description "LSP role type."; reference "RFC4872, section 4.2.1"; } leaf lsp-protection-state { type identityref { base te-types:lsp-protection-state; } description "The APS state machine controlling which tunnels are using the resources of the protecting LSP."; reference "RFC7271 and RFC8234"; } leaf protection-group-ingress-node-id { type te-types:te-node-id; description "Indicates the te-node-id of the protection group ingress node when the APS state represents an external command (LoP, SF, MS) applied to it or a WTR timer running on it. If the external command is not applied to the ingress node or the WTR timer is not running on it, this attribute is not specified. A value 0.0.0.0 is used when the te-node-id of the protection group ingress node is unknown (e.g., because the ingress node is outside the scope of control of the server)"; } leaf protection-group-egress-node-id { type te-types:te-node-id; description "Indicates the te-node-id of the protection group egress node when the APS state represents an external command (LoP, SF, MS) applied to it or a WTR timer running on it. If the external command is not applied to the ingress node or the WTR timer is not running on it, this attribute is not specified. A value 0.0.0.0 is used when the te-node-id of the protection group ingress node is unknown (e.g., because the ingress node is outside the scope of control of the server)"; } container lsp-actual-route-information { description "RSVP recorded route object information."; list lsp-actual-route-information { when "../../origin-type = 'ingress'" { description "Applicable on ingress LSPs only."; } key "index"; description "Record route list entry."; uses te-types:record-route-state; } } } } } /* TE Tunnel RPCs/execution Data */ rpc tunnels-path-compute { description "TE tunnels RPC nodes."; input { container path-compute-info { /* * An external path compute module may augment this * target. */ description "RPC input information."; } } output { container path-compute-result { /* * An external path compute module may augment this * target. */ description "RPC output information."; } } } rpc tunnels-actions { description "TE tunnels actions RPC"; input { container tunnel-info { description "TE tunnel information."; choice filter-type { mandatory true; description "Filter choice."; case all-tunnels { leaf all { type empty; mandatory true; description "When present, applies the action on all TE tunnels."; } } case one-tunnel { leaf tunnel { type tunnel-ref; description "Apply action on the specific TE tunnel."; } } } } container action-info { description "TE tunnel action information."; leaf action { type identityref { base te-types:tunnel-actions-type; } description "The action type."; } leaf disruptive { when "derived-from-or-self(../action, " + "'te:tunnel-action-reoptimize')"; type empty; description "When present, specifies whether or not the reoptimization action is allowed to be disruptive."; } } } output { leaf action-result { type identityref { base te-types:te-action-result; } description "The result of the tunnel action operation."; } } } } ]]>
TE Device YANG Model The device TE YANG module ('ietf-te-device') models data that is specific to managing a TE device. This module augments the generic TE YANG module.
Module Structure
TE Interfaces This branch of the model manages TE interfaces that are present on a device. Examples of TE interface properties are: Maximum reservable bandwidth, bandwidth constraints (BC) Flooding parameters Flooding intervals and threshold values Interface attributes (Extended) administrative groups SRLG values TE metric value Fast reroute backup tunnel properties (such as static, auto-tunnel) The derived state associated with interfaces is grouped under the interface "state" sub-container as shown in . This covers state data such as: Bandwidth information: maximum bandwidth, available bandwidth at different priorities and for each class-type (CT) List of admitted LSPs Name, bandwidth value and pool, time, priority Statistics: state counters, flooding counters, admission counters (accepted/rejected), preemption counters Adjacency information Neighbor address Metric value
> . +-- ro state <> ]]>
Tree Diagram shows the tree diagram of the device TE YANG model defined in modules 'ietf-te-device.yang'.
YANG Module The device TE YANG module 'ietf-te-device' imports the following module(s): ietf-interfaces defined in ietf-routing-types defined in ietf-te-types defined in ietf-te defined in this document
file "ietf-te-device@2022-10-12.yang" module ietf-te-device { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-te-device"; /* Replace with IANA when assigned */ prefix te-dev; /* Import TE module */ import ietf-te { prefix te; reference "RFCXXXX: A YANG Data Model for Traffic Engineering Tunnels and Interfaces"; } /* Import TE types */ import ietf-te-types { prefix te-types; reference "RFC8776: Common YANG Data Types for Traffic Engineering."; } import ietf-interfaces { prefix if; reference "RFC8343: A YANG Data Model for Interface Management"; } import ietf-routing-types { prefix rt-types; reference "RFC8294: Common YANG Data Types for the Routing Area"; } organization "IETF Traffic Engineering Architecture and Signaling (TEAS) Working Group"; contact "WG Web: WG List: Editor: Tarek Saad Editor: Rakesh Gandhi Editor: Vishnu Pavan Beeram Editor: Himanshu Shah Editor: Xufeng Liu Editor: Igor Bryskin "; description "This module defines a data model for TE device configurations, state, and RPCs. The model fully conforms to the Network Management Datastore Architecture (NMDA). Copyright (c) 2022 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Revised BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices."; // RFC Ed.: replace XXXX with actual RFC number and remove this // note. // RFC Ed.: update the date below with the date of RFC publication // and remove this note. revision 2022-10-12 { description "Initial revision for the TE device YANG module."; reference "RFCXXXX: A YANG Data Model for Traffic Engineering Tunnels and Interfaces"; } grouping lsp-device-timers { description "Device TE LSP timers configs."; leaf lsp-install-interval { type uint32; units "seconds"; description "TE LSP installation delay time."; } leaf lsp-cleanup-interval { type uint32; units "seconds"; description "TE LSP cleanup delay time."; } leaf lsp-invalidation-interval { type uint32; units "seconds"; description "TE LSP path invalidation before taking action delay time."; } } grouping te-igp-flooding-bandwidth-config { description "Configurable items for igp flooding bandwidth threshold configuration."; leaf threshold-type { type enumeration { enum delta { description "'delta' indicates that the local system should flood IGP updates when a change in reserved bandwidth >= the specified delta occurs on the interface."; } enum threshold-crossed { description "THRESHOLD-CROSSED indicates that the local system should trigger an update (and hence flood) the reserved bandwidth when the reserved bandwidth changes such that it crosses, or becomes equal to one of the threshold values."; } } description "The type of threshold that should be used to specify the values at which bandwidth is flooded. 'delta' indicates that the local system should flood IGP updates when a change in reserved bandwidth >= the specified delta occurs on the interface. Where 'threshold-crossed' is specified, the local system should trigger an update (and hence flood) the reserved bandwidth when the reserved bandwidth changes such that it crosses, or becomes equal to one of the threshold values."; } leaf delta-percentage { when "../threshold-type = 'delta'" { description "The percentage delta can only be specified when the threshold type is specified to be a percentage delta of the reserved bandwidth."; } type rt-types:percentage; description "The percentage of the maximum-reservable-bandwidth considered as the delta that results in an IGP update being flooded."; } leaf threshold-specification { when "../threshold-type = 'threshold-crossed'" { description "The selection of whether mirrored or separate threshold values are to be used requires user specified thresholds to be set."; } type enumeration { enum mirrored-up-down { description "mirrored-up-down indicates that a single set of threshold values should be used for both increasing and decreasing bandwidth when determining whether to trigger updated bandwidth values to be flooded in the IGP TE extensions."; } enum separate-up-down { description "separate-up-down indicates that a separate threshold values should be used for the increasing and decreasing bandwidth when determining whether to trigger updated bandwidth values to be flooded in the IGP TE extensions."; } } description "This value specifies whether a single set of threshold values should be used for both increasing and decreasing bandwidth when determining whether to trigger updated bandwidth values to be flooded in the IGP TE extensions. 'mirrored-up-down' indicates that a single value (or set of values) should be used for both increasing and decreasing values, where 'separate-up-down' specifies that the increasing and decreasing values will be separately specified."; } leaf-list up-thresholds { when "../threshold-type = 'threshold-crossed'" + "and ../threshold-specification = 'separate-up-down'" { description "A list of up-thresholds can only be specified when the bandwidth update is triggered based on crossing a threshold and separate up and down thresholds are required."; } type rt-types:percentage; description "The thresholds (expressed as a percentage of the maximum reservable bandwidth) at which bandwidth updates are to be triggered when the bandwidth is increasing."; } leaf-list down-thresholds { when "../threshold-type = 'threshold-crossed'" + "and ../threshold-specification = 'separate-up-down'" { description "A list of down-thresholds can only be specified when the bandwidth update is triggered based on crossing a threshold and separate up and down thresholds are required."; } type rt-types:percentage; description "The thresholds (expressed as a percentage of the maximum reservable bandwidth) at which bandwidth updates are to be triggered when the bandwidth is decreasing."; } leaf-list up-down-thresholds { when "../threshold-type = 'threshold-crossed'" + "and ../threshold-specification = 'mirrored-up-down'" { description "A list of thresholds corresponding to both increasing and decreasing bandwidths can be specified only when an update is triggered based on crossing a threshold, and the same up and down thresholds are required."; } type rt-types:percentage; description "The thresholds (expressed as a percentage of the maximum reservable bandwidth of the interface) at which bandwidth updates are flooded - used both when the bandwidth is increasing and decreasing."; } } /** * TE device augmentations */ augment "/te:te" { description "TE global container."; /* TE Interface Configuration Data */ container interfaces { description "Configuration data model for TE interfaces."; uses te-igp-flooding-bandwidth-config; list interface { key "interface"; description "TE interfaces."; leaf interface { type if:interface-ref; description "TE interface name."; } /* TE interface parameters */ leaf te-metric { type te-types:te-metric; description "TE interface metric."; } choice admin-group-type { description "TE interface administrative groups representation type."; case value-admin-groups { choice value-admin-group-type { description "choice of admin-groups."; case admin-groups { description "Administrative group/Resource class/Color."; leaf admin-group { type te-types:admin-group; description "TE interface administrative group."; } } case extended-admin-groups { if-feature "te-types:extended-admin-groups"; description "Extended administrative group/Resource class/Color."; leaf extended-admin-group { type te-types:extended-admin-group; description "TE interface extended administrative group."; } } } } case named-admin-groups { list named-admin-groups { if-feature "te-types:extended-admin-groups"; if-feature "te-types:named-extended-admin-groups"; key "named-admin-group"; description "A list of named admin-group entries."; leaf named-admin-group { type leafref { path "../../../../te:globals/" + "te:named-admin-groups/te:named-admin-group/" + "te:name"; } description "A named admin-group entry."; } } } } choice srlg-type { description "Choice of SRLG configuration."; case value-srlgs { list values { key "value"; description "List of SRLG values that this link is part of."; leaf value { type uint32 { range "0..4294967295"; } description "Value of the SRLG"; } } } case named-srlgs { list named-srlgs { if-feature "te-types:named-srlg-groups"; key "named-srlg"; description "A list of named SRLG entries."; leaf named-srlg { type leafref { path "../../../../te:globals/" + "te:named-srlgs/te:named-srlg/te:name"; } description "A named SRLG entry."; } } } } uses te-igp-flooding-bandwidth-config; list switching-capabilities { key "switching-capability"; description "List of interface capabilities for this interface."; leaf switching-capability { type identityref { base te-types:switching-capabilities; } description "Switching Capability for this interface."; } leaf encoding { type identityref { base te-types:lsp-encoding-types; } description "Encoding supported by this interface."; } } container state { config false; description "State parameters for interface TE metric."; container te-advertisements-state { description "TE interface advertisements state container."; leaf flood-interval { type uint32; description "The periodic flooding interval."; } leaf last-flooded-time { type uint32; units "seconds"; description "Time elapsed since last flooding in seconds."; } leaf next-flooded-time { type uint32; units "seconds"; description "Time remained for next flooding in seconds."; } leaf last-flooded-trigger { type enumeration { enum link-up { description "Link-up flooding trigger."; } enum link-down { description "Link-down flooding trigger."; } enum threshold-up { description "Bandwidth reservation up threshold."; } enum threshold-down { description "Bandwidth reservation down threshold."; } enum bandwidth-change { description "Bandwidth capacity change."; } enum user-initiated { description "Initiated by user."; } enum srlg-change { description "SRLG property change."; } enum periodic-timer { description "Periodic timer expired."; } } default "periodic-timer"; description "Trigger for the last flood."; } list advertised-level-areas { key "level-area"; description "List of level-areas that the TE interface is advertised in."; leaf level-area { type uint32; description "The IGP area or level where the TE interface link state is advertised in."; } } } } } } } /* TE globals device augmentation */ augment "/te:te/te:globals" { description "Global TE device specific configuration parameters."; uses lsp-device-timers; } /* TE tunnels device configuration augmentation */ augment "/te:te/te:tunnels/te:tunnel" { description "Tunnel device dependent augmentation."; leaf path-invalidation-action { type identityref { base te-types:path-invalidation-action-type; } description "Tunnel path invalidation action."; } uses lsp-device-timers; } /* TE LSPs device state augmentation */ augment "/te:te/te:lsps/te:lsp" { description "TE LSP device dependent augmentation."; container lsp-timers { when "../te:origin-type = 'ingress'" { description "Applicable to ingress LSPs only."; } description "Ingress LSP timers."; leaf uptime { type uint32; units "seconds"; description "The LSP uptime."; } leaf time-to-install { type uint32; units "seconds"; description "The time remaining for a new LSP to be instantiated in forwarding to carry traffic."; } leaf time-to-destroy { type uint32; units "seconds"; description "The time remaining for a existing LSP to be deleted from forwarding."; } } container downstream-info { when "../te:origin-type != 'egress'" { description "Downstream information of the LSP."; } description "downstream information."; leaf nhop { type te-types:te-tp-id; description "downstream next-hop address."; } leaf outgoing-interface { type if:interface-ref; description "downstream interface."; } container neighbor { uses te:te-generic-node-id; description "downstream neighbor address."; } leaf label { type rt-types:generalized-label; description "downstream label."; } } container upstream-info { when "../te:origin-type != 'ingress'" { description "Upstream information of the LSP."; } description "upstream information."; leaf phop { type te-types:te-tp-id; description "upstream next-hop or previous-hop address."; } container neighbor { uses te:te-generic-node-id; description "upstream neighbor address."; } leaf label { type rt-types:generalized-label; description "upstream label."; } } } /* TE interfaces RPCs/execution Data */ rpc link-state-update { description "Triggers a link state update for the specific interface."; input { choice filter-type { mandatory true; description "Filter choice."; case match-all { leaf all { type empty; mandatory true; description "Match all TE interfaces."; } } case match-one-interface { leaf interface { type if:interface-ref; description "Match a specific TE interface."; } } } } } } ]]>
Notifications Notifications are a key component of any topology data model. and define a subscription mechanism and a push mechanism for YANG datastores. These mechanisms currently allow the user to: Subscribe to notifications on a per-client basis. Specify subtree filters or XML Path Language (XPath) filters so that only contents of interest will be sent. Specify either periodic or on-demand notifications.
IANA Considerations This document registers the following URIs in the IETF XML registry . Following the format in , the following registrations are requested to be made.
This document registers two YANG modules in the YANG Module Names registry .
Security Considerations The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF or RESTCONF . The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) . The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS . The Network Configuration Access Control Model (NACM) provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability: "/te/globals": This module specifies the global TE configurations on a device. Unauthorized access to this container could cause the device to ignore packets it should receive and process. "/te/tunnels": This list specifies the configuration and state of TE Tunnels present on the device or controller. Unauthorized access to this list could cause the device to ignore packets it should receive and process. An attacker may also use state to derive information about the network topology, and subsequently orchestrate further attacks. "/te/interfaces": This list specifies the configuration and state TE interfaces on a device. Unauthorized access to this list could cause the device to ignore packets it should receive and process. Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability: "/te/lsps": this list contains information state about established LSPs in the network. An attacker can use this information to derive information about the network topology, and subsequently orchestrate further attacks. Some of the RPC operations in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control access to these operations. These are the operations and their sensitivity/vulnerability: "/te/tunnels-actions": using this RPC, an attacker can modify existing paths that may be carrying live traffic, and hence result to interruption to services carried over the network. "/te/tunnels-path-compute": using this RPC, an attacker can retrieve secured information about the network provider which can be used to orchestrate further attacks. The security considerations spelled out in the YANG 1.1 specification apply for this document as well.
Acknowledgement The authors would like to thank the members of the multi-vendor YANG design team who are involved in the definition of this model. The authors would like to thank Tom Petch and Adrian Farrel for reviewing and providing useful feedback about the document. The authors would also like to thank Loa Andersson, Lou Berger, Sergio Belotti, Italo Busi, Carlo Perocchio, Francesco Lazzeri, Aihua Guo, Dhruv Dhody, and Raqib Jones for providing feedback on this document.
Contributors
Appendix A: Data Tree Examples This section contains examples of use of the model with RESTCONF and JSON encoding. For the example we will use a 4 node MPLS network were RSVP-TE MPLS Tunnels can be setup. The loopbacks of each router are shown. The network in will be used in the examples described in the following sections.
Basic Tunnel Setup This example uses the TE Tunnel YANG data model defined in this document to create an RSVP-TE signaled Tunnel of packet LSP encoding type. First, the TE Tunnel is created with no specific restrictions or constraints (e.g., protection or restoration). The TE Tunnel ingresses on router A and egresses on router D. In this case, the TE Tunnel is created without specifying additional information about the primary paths.
Global Named Path Constraints This example uses the YANG data model to create a 'named path constraint' that can be reference by TE Tunnels. The path constraint, in this case, limits the TE Tunnel hops for the computed path.
Tunnel with Global Path Constraint In this example, the previously created 'named path constraint' is applied to the TE Tunnel created in .
Tunnel with Per-tunnel Path Constraint In this example, the a per tunnel path constraint is explicitly indicated under the TE Tunnel created in to constrain the computed path for the tunnel.
Tunnel State In this example, the 'GET' query is sent to return the state stored about the tunnel.
The request, with status code 200 would include, for example, the following json:
Example TE Tunnel with Primary and Secondary Paths
Below is the state retrieved for a TE tunnel from source 192.0.2.1 to 192.0.2.5 with primary, secondary, reverse, and secondary reverse paths as shown in .
Appendix B: Full Model Tree Diagram shows the full tree diagram of the TE YANG model defined in module 'ietf-te.yang'.
/te/lsps/lsp/tunnel-name +--ro node? leafref +--ro lsp-id? leafref grouping path-computation-response: +--ro computed-paths-properties | +--ro computed-path-properties* [k-index] | +--ro k-index? uint8 | +---u te-types:generic-path-properties +--ro computed-path-error-infos +--ro computed-path-error-info* [] +--ro error-description? string +--ro error-timestamp? yang:date-and-time +--ro error-reason? identityref grouping protection-restoration-properties: +-- protection | +-- enable? boolean | +-- protection-type? identityref | +-- protection-reversion-disable? boolean | +-- hold-off-time? uint32 | +-- wait-to-revert? uint16 | +-- aps-signal-id? uint8 +-- restoration +-- restoration-type? identityref +-- restoration-scheme? identityref +-- restoration-reversion-disable? boolean +-- hold-off-time? uint32 +-- wait-to-restore? uint16 +-- wait-to-revert? uint16 grouping tunnel-associations-properties: +-- association-objects +-- association-object* [association-key] | +-- association-key? string | +-- type? identityref | +-- id? uint16 | +-- source | +---u te-generic-node-id +-- association-object-extended* [association-key] +-- association-key? string +-- type? identityref +-- id? uint16 +-- source | +---u te-generic-node-id +-- global-source? uint32 +-- extended-id? yang:hex-string grouping tunnel-common-attributes: +-- source? te-types:te-node-id +-- destination? te-types:te-node-id +-- src-tunnel-tp-id? binary +-- dst-tunnel-tp-id? binary +-- bidirectional? boolean grouping tunnel-hierarchy-properties: +-- hierarchy +-- dependency-tunnels | +-- dependency-tunnel* [name] | +-- name? | | -> /te/tunnels/tunnel/name | +---u te-types:encoding-and-switching-type +-- hierarchical-link +-- enable? boolean +-- local-te-node-id? te-types:te-node-id +-- local-te-link-tp-id? te-types:te-tp-id +-- remote-te-node-id? te-types:te-node-id +---u te-types:te-topology-identifier grouping path-constraints-common: +---u te-types:common-path-constraints-attributes +---u te-types:generic-path-disjointness +---u te-types:path-constraints-route-objects +-- path-in-segment! | +---u te-types:label-set-info +-- path-out-segment! +---u te-types:label-set-info ]]>
 RSVP-TE: Extensions to RSVP for LSP Tunnels This document describes the use of RSVP (Resource Reservation Protocol), including all the necessary extensions, to establish label-switched paths (LSPs) in MPLS (Multi-Protocol Label Switching). Since the flow along an LSP is completely identified by the label applied at the ingress node of the path, these paths may be treated as tunnels. A key application of LSP tunnels is traffic engineering with MPLS as specified in RFC 2702. [STANDARDS-TRACK] Key words for use in RFCs to Indicate Requirement Levels In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF) YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK] Network Configuration Protocol (NETCONF) The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK] Common YANG Data Types This document introduces a collection of common data types to be used with the YANG data modeling language. This document obsoletes RFC 6021. Procedures for Dynamically Signaled Hierarchical Label Switched Paths Label Switched Paths (LSPs) set up in Multiprotocol Label Switching (MPLS) or Generalized MPLS (GMPLS) networks can be used to form links to carry traffic in those networks or in other (client) networks.Protocol mechanisms already exist to facilitate the establishment of such LSPs and to bundle traffic engineering (TE) links to reduce the load on routing protocols. This document defines extensions to those mechanisms to support identifying the use to which such LSPs are to be put and to enable the TE link endpoints to be assigned addresses or unnumbered identifiers during the signaling process. [STANDARDS-TRACK] RESTCONF Protocol This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF). The YANG 1.1 Data Modeling Language YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF). Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions This document describes extensions to Multi-Protocol Label Switching (MPLS) Resource ReserVation Protocol - Traffic Engineering (RSVP-TE) signaling required to support Generalized MPLS. Generalized MPLS extends the MPLS control plane to encompass time-division (e.g., Synchronous Optical Network and Synchronous Digital Hierarchy, SONET/SDH), wavelength (optical lambdas) and spatial switching (e.g., incoming port or fiber to outgoing port or fiber). This document presents a RSVP-TE specific description of the extensions. A generic functional description can be found in separate documents. [STANDARDS-TRACK] Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. Common YANG Data Types for the Routing Area This document defines a collection of common data types using the YANG data modeling language. These derived common types are designed to be imported by other modules defined in the routing area. Common YANG Data Types for Traffic Engineering This document defines a collection of common data types and groupings in YANG data modeling language. These derived common types and groupings are intended to be imported by modules that model Traffic Engineering (TE) configuration and state capabilities. YANG Tree Diagrams This document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language. Network Management Datastore Architecture (NMDA) Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model. This document updates RFC 7950. The BGP Tunnel Encapsulation Attribute This document defines a BGP path attribute known as the "Tunnel Encapsulation attribute", which can be used with BGP UPDATEs of various Subsequent Address Family Identifiers (SAFIs) to provide information needed to create tunnels and their corresponding encapsulation headers. It provides encodings for a number of tunnel types, along with procedures for choosing between alternate tunnels and routing packets into tunnels.This document obsoletes RFC 5512, which provided an earlier definition of the Tunnel Encapsulation attribute. RFC 5512 was never deployed in production. Since RFC 5566 relies on RFC 5512, it is likewise obsoleted. This document updates RFC 5640 by indicating that the Load-Balancing Block sub-TLV may be included in any Tunnel Encapsulation attribute where load balancing is desired. YANG Data Model for Traffic Engineering (TE) Topologies This document defines a YANG data model for representing, retrieving, and manipulating Traffic Engineering (TE) Topologies. The model serves as a base model that other technology-specific TE topology models can augment. Label Switched Paths (LSP) Hierarchy with Generalized Multi-Protocol Label Switching (GMPLS) Traffic Engineering (TE) To improve scalability of Generalized Multi-Protocol Label Switching (GMPLS) it may be useful to aggregate Label Switched Paths (LSPs) by creating a hierarchy of such LSPs. A way to create such a hierarchy is by (a) a Label Switching Router (LSR) creating a Traffic Engineering Label Switched Path (TE LSP), (b) the LSR forming a forwarding adjacency (FA) out of that LSP (by advertising this LSP as a Traffic Engineering (TE) link into the same instance of ISIS/OSPF as the one that was used to create the LSP), (c) allowing other LSRs to use FAs for their path computation, and (d) nesting of LSPs originated by other LSRs into that LSP (by using the label stack construct).This document describes the mechanisms to accomplish this. [PROPOSED STANDARD] Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS) This document defines a common terminology for Generalized Multi-Protocol Label Switching (GMPLS)-based recovery mechanisms (i.e., protection and restoration). The terminology is independent of the underlying transport technologies covered by GMPLS. This memo provides information for the Internet community. RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery This document describes protocol-specific procedures and extensions for Generalized Multi-Protocol Label Switching (GMPLS) Resource ReSerVation Protocol - Traffic Engineering (RSVP-TE) signaling to support end-to-end Label Switched Path (LSP) recovery that denotes protection and restoration. A generic functional description of GMPLS recovery can be found in a companion document, RFC 4426. [STANDARDS-TRACK] RSVP ASSOCIATION Object Extensions The RSVP ASSOCIATION object was defined in the context of GMPLS-controlled Label Switched Paths (LSPs). In this context, the object is used to associate recovery LSPs with the LSP they are protecting. This object also has broader applicability as a mechanism to associate RSVP state. This document defines how the ASSOCIATION object can be more generally applied. This document also defines Extended ASSOCIATION objects that, in particular, can be used in the context of the MPLS Transport Profile (MPLS-TP). This document updates RFC 2205, RFC 3209, and RFC 3473. It also generalizes the definition of the Association ID field defined in RFC 4872. [STANDARDS-TRACK] OSPF Traffic Engineering (TE) Metric Extensions In certain networks, such as, but not limited to, financial information networks (e.g., stock market data providers), network performance information (e.g., link propagation delay) is becoming critical to data path selection.This document describes common extensions to RFC 3630 "Traffic Engineering (TE) Extensions to OSPF Version 2" and RFC 5329 "Traffic Engineering Extensions to OSPF Version 3" to enable network performance information to be distributed in a scalable fashion. The information distributed using OSPF TE Metric Extensions can then be used to make path selection decisions based on network performance.Note that this document only covers the mechanisms by which network performance information is distributed. The mechanisms for measuring network performance information or using that information, once distributed, are outside the scope of this document. IS-IS Traffic Engineering (TE) Metric Extensions In certain networks, such as, but not limited to, financial information networks (e.g., stock market data providers), network-performance criteria (e.g., latency) are becoming as critical to data-path selection as other metrics.This document describes extensions to IS-IS Traffic Engineering Extensions (RFC 5305). These extensions provide a way to distribute and collect network-performance information in a scalable fashion. The information distributed using IS-IS TE Metric Extensions can then be used to make path-selection decisions based on network performance.Note that this document only covers the mechanisms with which network-performance information is distributed. The mechanisms for measuring network performance or acting on that information, once distributed, are outside the scope of this document.This document obsoletes RFC 7810. Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE A stateful Path Computation Element (PCE) has access to not only the information disseminated by the network's Interior Gateway Protocol (IGP) but also the set of active paths and their reserved resources for its computation. The additional Label Switched Path (LSP) state information allows the PCE to compute constrained paths while considering individual LSPs and their interactions. This requires a State Synchronization mechanism between the PCE and the network, the PCE and Path Computation Clients (PCCs), and cooperating PCEs. The basic mechanism for State Synchronization is part of the stateful PCE specification. This document presents motivations for optimizations to the base State Synchronization procedure and specifies the required Path Computation Element Communication Protocol (PCEP) extensions. MPLS Transport Profile (MPLS-TP) Linear Protection to Match the Operational Expectations of Synchronous Digital Hierarchy, Optical Transport Network, and Ethernet Transport Network Operators This document describes alternate mechanisms to perform some of the functions of MPLS Transport Profile (MPLS-TP) linear protection defined in RFC 6378, and also defines additional mechanisms. The purpose of these alternate and additional mechanisms is to provide operator control and experience that more closely models the behavior of linear protection seen in other transport networks.This document also introduces capabilities and modes for linear protection. A capability is an individual behavior, and a mode is a particular combination of capabilities. Two modes are defined in this document: Protection State Coordination (PSC) mode and Automatic Protection Switching (APS) mode.This document describes the behavior of the PSC protocol including priority logic and state machine when all the capabilities associated with the APS mode are enabled.This document updates RFC 6378 in that the capability advertisement method defined here is an addition to that document. Updates to MPLS Transport Profile (MPLS-TP) Linear Protection in Automatic Protection Switching (APS) Mode This document contains updates to MPLS Transport Profile (MPLS-TP) linear protection in Automatic Protection Switching (APS) mode defined in RFC 7271. The updates provide rules related to the initialization of the Protection State Coordination (PSC) Control Logic (in which the state machine resides) when operating in APS mode and clarify the operation related to state transition table lookup. Extended Administrative Groups in MPLS Traffic Engineering (MPLS-TE) MPLS Traffic Engineering (MPLS-TE) advertises 32 administrative groups (commonly referred to as "colors" or "link colors") using the Administrative Group sub-TLV. This is defined for OSPFv2 (RFC 3630), OSPFv3 (RFC 5329) and IS-IS (RFC 5305).This document adds a sub-TLV to the IGP TE extensions, "Extended Administrative Group". This sub-TLV provides for additional administrative groups (link colors) beyond the current limit of 32. A YANG Data Model for Interface Management This document defines a YANG data model for the management of network interfaces. It is expected that interface-type-specific data models augment the generic interfaces data model defined in this document. The data model includes definitions for configuration and system state (status information and counters for the collection of statistics).The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA) defined in RFC 8342.This document obsoletes RFC 7223. Subscription to YANG Notifications This document defines a YANG data model and associated mechanisms enabling subscriber-specific subscriptions to a publisher's event streams. Applying these elements allows a subscriber to request and receive a continuous, customized feed of publisher-generated information. Subscription to YANG Notifications for Datastore Updates This document describes a mechanism that allows subscriber applications to request a continuous and customized stream of updates from a YANG datastore. Providing such visibility into updates enables new capabilities based on the remote mirroring and monitoring of configuration and operational state. The IETF XML Registry This document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas. Using the NETCONF Protocol over Secure Shell (SSH) This document describes a method for invoking and running the Network Configuration Protocol (NETCONF) within a Secure Shell (SSH) session as an SSH subsystem. This document obsoletes RFC 4742. [STANDARDS-TRACK] The Transport Layer Security (TLS) Protocol Version 1.3 This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery.This document updates RFCs 5705 and 6066, and obsoletes RFCs 5077, 5246, and 6961. This document also specifies new requirements for TLS 1.2 implementations. Network Configuration Access Control Model The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model.This document obsoletes RFC 6536. Segment Routing Policy Architecture Segment Routing (SR) allows a node to steer a packet flow along any path. Intermediate per-path states are eliminated thanks to source routing. SR Policy is an ordered list of segments (i.e., instructions) that represent a source-routed policy. Packet flows are steered into an SR Policy on a node where it is instantiated called a headend node. The packets steered into an SR Policy carry an ordered list of segments associated with that SR Policy.This document updates RFC 8402 as it details the concepts of SR Policy and steering into an SR Policy. Generalized Multi-Protocol Label Switching (GMPLS) Architecture Future data and transmission networks will consist of elements such as routers, switches, Dense Wavelength Division Multiplexing (DWDM) systems, Add-Drop Multiplexors (ADMs), photonic cross-connects (PXCs), optical cross-connects (OXCs), etc. that will use Generalized Multi-Protocol Label Switching (GMPLS) to dynamically provision resources and to provide network survivability using protection and restoration techniques. This document describes the architecture of GMPLS. GMPLS extends MPLS to encompass time-division (e.g., SONET/SDH, PDH, G.709), wavelength (lambdas), and spatial switching (e.g., incoming port or fiber to outgoing port or fiber). The focus of GMPLS is on the control plane of these various layers since each of them can use physically diverse data or forwarding planes. The intention is to cover both the signaling and the routing part of that control plane. [STANDARDS-TRACK]